Nuclear spinning resonance procedures and devices to suppress a signal from a chemical displacement component from a long-term relaxation-weighted nuclear spinotogram.

摘要

MRI sequences are known for lipid suppression in an image. With an amplitude modulated rf-pulse lipid spin nuclei are selectively excited and thereafter at the zerocrossing point of the T1 relaxation of the lipid signal spin echoes are excited with a spin echo scheme. Said sequence will give rise to image artifacts if there are relatively large rf field inhomogeneities. It is suggested to improve said sequency by selectively inverting a chemical shift component by means of an adiabatic fast passage rf pulse prior to spin echo excitation. The improved sequency shows excellent results even with relatively large rf inhomogeneities occuring e.g. when using linearly polarized rf fields.